Deflect Missiles

[Melkyor]

Hello,
I don't understand how the Deflect Missiles macro is supposed to work.
I created 2 macros on my side, "DeflectMissiles" and "DeflectMissilesCallback", using exactly the code you created.
Whatever I do next, absolutely nothing happens when I execute them.
Where should I call the macro? From the Item Deflect Missiles (Macro OnUse) or from an Active Effect (macro.execute).

How is this supposed to work then?

Thank you in advance for your help